package rmy.device.onbon;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class BxUtils {

    public enum ENDIAN {LITTLE, BIG}

    private static final int[] crc16_table = new int[] {
            0X0000, 0XC0C1, 0XC181, 0X0140, 0XC301, 0X03C0, 0X0280, 0XC241,
            0XC601, 0X06C0, 0X0780, 0XC741, 0X0500, 0XC5C1, 0XC481, 0X0440,
            0XCC01, 0X0CC0, 0X0D80, 0XCD41, 0X0F00, 0XCFC1, 0XCE81, 0X0E40,
            0X0A00, 0XCAC1, 0XCB81, 0X0B40, 0XC901, 0X09C0, 0X0880, 0XC841,
            0XD801, 0X18C0, 0X1980, 0XD941, 0X1B00, 0XDBC1, 0XDA81, 0X1A40,
            0X1E00, 0XDEC1, 0XDF81, 0X1F40, 0XDD01, 0X1DC0, 0X1C80, 0XDC41,
            0X1400, 0XD4C1, 0XD581, 0X1540, 0XD701, 0X17C0, 0X1680, 0XD641,
            0XD201, 0X12C0, 0X1380, 0XD341, 0X1100, 0XD1C1, 0XD081, 0X1040,
            0XF001, 0X30C0, 0X3180, 0XF141, 0X3300, 0XF3C1, 0XF281, 0X3240,
            0X3600, 0XF6C1, 0XF781, 0X3740, 0XF501, 0X35C0, 0X3480, 0XF441,
            0X3C00, 0XFCC1, 0XFD81, 0X3D40, 0XFF01, 0X3FC0, 0X3E80, 0XFE41,
            0XFA01, 0X3AC0, 0X3B80, 0XFB41, 0X3900, 0XF9C1, 0XF881, 0X3840,
            0X2800, 0XE8C1, 0XE981, 0X2940, 0XEB01, 0X2BC0, 0X2A80, 0XEA41,
            0XEE01, 0X2EC0, 0X2F80, 0XEF41, 0X2D00, 0XEDC1, 0XEC81, 0X2C40,
            0XE401, 0X24C0, 0X2580, 0XE541, 0X2700, 0XE7C1, 0XE681, 0X2640,
            0X2200, 0XE2C1, 0XE381, 0X2340, 0XE101, 0X21C0, 0X2080, 0XE041,
            0XA001, 0X60C0, 0X6180, 0XA141, 0X6300, 0XA3C1, 0XA281, 0X6240,
            0X6600, 0XA6C1, 0XA781, 0X6740, 0XA501, 0X65C0, 0X6480, 0XA441,
            0X6C00, 0XACC1, 0XAD81, 0X6D40, 0XAF01, 0X6FC0, 0X6E80, 0XAE41,
            0XAA01, 0X6AC0, 0X6B80, 0XAB41, 0X6900, 0XA9C1, 0XA881, 0X6840,
            0X7800, 0XB8C1, 0XB981, 0X7940, 0XBB01, 0X7BC0, 0X7A80, 0XBA41,
            0XBE01, 0X7EC0, 0X7F80, 0XBF41, 0X7D00, 0XBDC1, 0XBC81, 0X7C40,
            0XB401, 0X74C0, 0X7580, 0XB541, 0X7700, 0XB7C1, 0XB681, 0X7640,
            0X7200, 0XB2C1, 0XB381, 0X7340, 0XB101, 0X71C0, 0X7080, 0XB041,
            0X5000, 0X90C1, 0X9181, 0X5140, 0X9301, 0X53C0, 0X5280, 0X9241,
            0X9601, 0X56C0, 0X5780, 0X9741, 0X5500, 0X95C1, 0X9481, 0X5440,
            0X9C01, 0X5CC0, 0X5D80, 0X9D41, 0X5F00, 0X9FC1, 0X9E81, 0X5E40,
            0X5A00, 0X9AC1, 0X9B81, 0X5B40, 0X9901, 0X59C0, 0X5880, 0X9841,
            0X8801, 0X48C0, 0X4980, 0X8941, 0X4B00, 0X8BC1, 0X8A81, 0X4A40,
            0X4E00, 0X8EC1, 0X8F81, 0X4F40, 0X8D01, 0X4DC0, 0X4C80, 0X8C41,
            0X4400, 0X84C1, 0X8581, 0X4540, 0X8701, 0X47C0, 0X4680, 0X8641,
            0X8201, 0X42C0, 0X4380, 0X8341, 0X4100, 0X81C1, 0X8081, 0X4040
    };

    //
    // 将字节转换成short 型
    public static final short bytesToShort(byte[] src, int start, ENDIAN endian) {

        short result = 0;

        if(endian == ENDIAN.LITTLE) {
            result = src[start+1];
            result <<= 8;
            result |= (((short)src[start]) & 0x00ff);
        }
        else {
            result = src[start];
            result <<= 8;
            result |= (((short)src[start+1]) & 0x00ff);
        }

        return result;
    }


    /**
     * 用于对数据哉进行校验的 CRC16 算法
     * @param	data	将要进行CRC16校验的原始数据
     * @return	校验值
     * @note	none
     */
    public static short CRC16(byte[] data, int offset, int length) {

        int crc = 0x0000;

        int a, b;
        byte d0;

        for(int i=0; i<length; i++) {
            //crc =  (short)(((crc) >> 8 ) ^ crc16_table[((crc) ^ (d0)) & 0xFF]);

            d0 = data[offset+i];

            a = (crc ^ d0) & 0xff;
            b = crc16_table[a];
            crc = (crc >> 8);
            crc = crc ^ b;
        }

        return (short)(crc & 0xffff);
    }

    /**
     * 用于对数据哉进行校验的 CRC16 算法
     * @param	data	将要进行CRC16校验的原始数据
     * @return	校验值
     * @note	none
     */
    public static byte calcXorCrc(byte[] data, int len) {

        byte crc = 0x00;

        for(int i = 0; i<len; i++) {
            crc ^= data[i];
        }

        return crc;
    }

    public static String dateToString(Date model) {
        //
        SimpleDateFormat ft;
        ft  = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        return (ft.format(model));
    }

    public static Date dateFromString(String data) {

        SimpleDateFormat ft;
        Date model;

        if(data != null) {
            ft = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

            try {
                model = ft.parse(data);
            } catch (ParseException e) {
                e.printStackTrace();
                //
                // 返回当时间
                model = new Date(System.currentTimeMillis());
            }
        }
        else {
            model = new Date(System.currentTimeMillis());
        }

        return model;
    }

    public static short byteSwap(short src) {

        short result;

        result = (short) ((src >> 8) | (src << 8));

        //
        return result;
    }
}
